IGF1 levels in mice with GRF signaling deficiency (black bars) compared to normal controls (white bars). Asterisks indicate significant differences. From Sun LY, Spong A, Swindell WR, et al., Growth hormone-releasing hormone disruption extends lifespan and regulates response to caloric restriction in mice. eLife. 2013;2:e01098, reproduced under the terms of the Creative Commons Attribution License. For More Info Visit: https://www.blueskypeptide.com/blog/modgrf-study-ghrh-r/